Control device for selectively fluidically connecting and disconnecting fluid connection points

ABSTRACT

The invention relates to a control device for selectively fluidically connecting and disconnecting fluid connection points (A, P, T) by means of a valve apparatus ( 1, 5 ), which controls fluid-conducting connection channels ( 55, 57, 59 ) extending between the connection points (A, P, T), which connection channels are arranged in a control block ( 3 ), into which the valve apparatus ( 1, 5 ) is at least partially inserted. The control device is characterized in that, proceeding from the respective fluid connection points (A, P, T), the connection channels ( 55, 59, 57 ) respectively connected to the fluid connection points extend in parallel to each other until the connection channels lead into a respective associated control chamber ( 49; 53, 51 ) of the valve apparatus ( 1, 5 ) and that the valve apparatus ( 1, 5 ) is retained in a receptacle ( 39 ), which separates at least two adjacently arranged control chambers ( 49, 51 ) from each other.

The invention relates to a control device for selectively fluidically connecting and disconnecting fluid connection points by means of a valve apparatus, which controls fluid-conducting connection channels extending between the connection points, which connection channels are arranged in a control block, into which the valve apparatus is at least partially inserted.

Control devices of this type are very frequently used for mobile work machines for the electro-hydraulic control of couplings and hydraulic actuating elements. Valve apparatuses in the form of so-called proportional pressure control valves, such as 3/2-way gate valves, are usually used in this context. The couplings and hydraulic actuating elements to be controlled are built into transmission casings in these applications. The valve apparatuses are usually formed by so-called cartridge valves inserted into a corresponding control block, with the control blocks being flange-mounted at the sides on the respective transmission. In light of the fact that, in the case of tractor transmissions, for example, more than ten valves may be required in order to control couplings and actuators, and that each of the valves is to be connected to a pump connection and a tank connection, and the working connection of each valve is to be connected to the respective coupling or actuating element to be controlled, there is considerable construction expenditure and cost expenditure is involved in the formation of the required fluid connection paths together with the associated pipework.

In light of this problem, the objective of the invention is to provide a control device of the aforementioned type, which is distinguished by a design that can be economically produced and an advantageous operating behavior.

This objective is achieved according to the invention by means of a control device having the features of claim 1 in its entirety.

According to the characterizing portion of claim 1, a significant distinctive feature of the invention is that, proceeding from the respective fluid connection points, the connection channels respectively connected to the fluid connection points are arranged extending parallel to each other until the connection channels open into a respective assigned control chamber of the valve apparatus and that the valve apparatus is held in a receptacle, which separates at least two adjacently arranged control chambers from each other. Because the receptacle, which forms a seat for the valve apparatus in the installation space, forms a sealing point between control chambers, which are axially offset relative to each other in the case of the gate valves in question, terrace steps which are axially offset relative to each other are formed in the installation space, so that it becomes possible to form terminal connection channels in a simple and economical manner by means of bores extending in parallel, which can extend in any direction relative to the valve axis, i.e. also vertically or slightly inclined. Since the connection channels to the respective steps of the valve, which are offset relative to each other in axial steps in the case of the valves in question, such as cartridge valves, no longer have to extend vertically relative to the valve axis, there is the particularly advantageous option of forming connection channels extending parallel in any direction relative to the valve axis, for example parallel to the valve axis or slightly inclined relative to the valve axis. The ability to freely configure permits an economical production and a design with very short fluid connection paths, which improves the dynamics of the operating behavior. Advantageously, the valve apparatus can be provided with a casing, which itself at least partially forms a control chamber and/or which has at least one bore, which opens into a control chamber. This results in particularly short fluid connection paths.

In particularly advantageous exemplary embodiments, in view of the parallel arrangement of the connection channels, the receptacle for the valve apparatus can be accommodated eccentric relative to the displacement axis of the valve gate, which is longitudinally-displaceably guided inside the valve casing, in the control block.

Particularly advantageously, the arrangement can be such that the receptacle is formed from a circular cylindrical receiving plate, which has a preferably circular cylindrical recess for receiving the valve casing, the center axis of which extending parallel to the center axis of the receiving plate is arranged offset relative to same. This offset allows the connection channel bypassing the receiving plate to bring the recess closer to the valve axis according to the eccentricity, and this results in a saving of installation space required for the control block.

As a result, in a particular advantageous manner, the connection channel for the pressure supply connection and the connection channel for the service connection can take up, with their respective longitudinal axis, approximately the same distance to the displacement axis of the valve gate, with the longitudinal axis of the connection channel for the tank connection or return connection being able to be coextensive with the displacement axis of the valve gate.

The pressure supply connection channel extending in the control block can be formed such that it is longer than the service connection connecting channel in the axial direction, and this, in turn, can be formed such that it is longer than the tank connection channel.

In addition, in advantageous exemplary embodiments the arrangement can be such that the control chamber into which the pressure supply connection channel opens lies above the control chamber into which the service connection connecting channel opens, viewed in the actuation direction of the valve gate, with these two control chambers being separated from each other in a fluid-tight manner by means of the receptacle.

With this arrangement of the receptacle, the control chamber into which the service connection connecting channel opens can lie above the control chamber into which the tank connection channel opens, viewed in the actuation direction of the valve gate, with these two adjacent control chambers being separated from each other in a fluid-tight manner by means of valve casing parts, which are encompassed by parts of the control block.

In particularly advantageous exemplary embodiments, the plate forming the receptacle can be encompassed on the outer peripheral side by a sealing device, which produces the seal between the receptacle and the control block.

A particular advantage of the invention is that the control block can be a component of a transmission casing, in particular a mobile work machine, or can be attached to the transmission casing. This permits, in particular in the case of complete elimination of the control block, a significant cost saving, associated with a corresponding reduction of the required installation space, simplification through less effort invested in pipework and improvement of the operating behavior through better dynamics as a result of shorter connection paths.

The invention is explained in detail below with reference to an exemplary embodiment depicted in the drawings, in which:

FIG. 1 shows a longitudinal section of an exemplary embodiment of the control device according to the invention;

FIG. 2 shows a side view of the exemplary embodiment, wherein the installation space area of an assigned control block is depicted in a longitudinal section, and

FIG. 3 shows a cross section along the cut line III-III of FIG. 2.

In the control device depicted in the figures the valve apparatus has a proportional pressure control valve which, in the form of a cartridge valve that can be actuated electromagnetically, is installed with its valve casing 1 in a control block 3. The control block 3 forms, in a conventional manner, fluid connection points, of which a pressure supply connection is identified with P, a service connection with A and a return connection or tank connection with T. A valve piston 5 longitudinally-displaceably guided in the valve casing 1 can be controlled by means of an actuating device 7 in the form of a so-called actuating magnet so as to assume its individual displacement positions. The actuating device 7 is designed in accordance with the prior art and has, for the purpose of displacement of a magnet armature 9, a coil winding 13 that can be powered by means of a plug 11. The actuating device 7 is designed as a so-called repelling magnet, i.e. when the coil winding 13 is powered, the magnet armature 9 moves downwards viewed in the viewing direction in FIG. 1 and exerts, by means of an actuating plunger 15, which is formed by an extension of the valve piston 5, a force on this valve piston, which triggers a displacement movement of the valve piston 5.

The actuating device 7 has a pole core 17 which, in the installed state, extends with its end 19 into the installation space of the control block 3, with a sealing element 21 forming the seal of the installation space. In the installed state, a flange ring 23, which abuts a step 25 of the pole core 17, forms a flange connection with the control block 3 by means of fastening screws 27. The above-described design of the valve apparatus, including a valve spring 29, which holds the valve piston 5 such that it bears on the magnet armature 9 in a non-positive manner, and a weak-effect counteracting spring 31 on the magnet piston 9, is known per se. In a likewise known manner, an axial bore 33 in the valve piston 5 forms, together with a transverse bore 35 and via an inclined bore 37 formed in the magnet piston 9, a channel for a pressure equalization in the case of displacement movements of magnet armature 9 and valve piston 5, as is likewise known per se in the case of such valve apparatuses.

As the figures show, a receiving plate 39 is provided in the installation space in the control block 3 as a receptacle, which forms a seat for the valve casing 1, which receiving plate has the shape of a circular cylindrical body, which has a circular cylindrical recess 41 (FIG. 1), through which the valve casing 1 extends with its circular cylindrical end part 43, with the outer periphery of the end part 43 abutting the recess 41 in a fluid-tight manner. On the outer periphery, the receiving plate 39 is sealed by means of a sealing element 45 on the control block 3, where the receiving plate 39 abuts a step 47 formed in the installation space. In this arrangement, the receiving plate 39 forms a fluid-tight partition between a control chamber 49 lying at the top in FIGS. 1 and 2 and a lower control chamber 51 which, in the conventional manner for cartridge valves, are surrounded by fluid passages of the valve casing 1, which are formed by bores 50 and 52. The valve casing 1 forms a third control chamber 53 with its open end on the end part 43.

Connection channels are formed in the control block 3 for the fluid connection between the connection points for the pressure connection P, the tank connection T and the service connection A and the assigned control chambers 49, 53 and 51 respectively. Each of these is formed by bores parallel to the displacement axis of the valve piston 5, of which one bore 55, located at a distance to the displacement axis, connects the pressure supply connection P to the associated control chamber 49. A bore 57, likewise located at a distance to the displacement axis, connects the service connection point A to the control chamber 51. A third bore 59 coaxial to the displacement axis connects the tank connection point T via the open end of the valve casing 1 to the control chamber 53. The latter is sealed relative to the control chamber 51 of the service connection A by means of a casing part 42 of the control block 3, which encompasses the end part 43 of the valve casing 1. As can be seen from the figures, the bore 55 leading to the top control chamber 49 bypasses the receiving plate 39, while the bore 57, which leads to the control chamber 51 lying on a lower step, is delimited in the upwards direction by the receiving plate 39. For this purpose, the round body forming the receiving plate 39 has a diameter of such dimensions that it overlaps the bore 57 and, at its circumferential edge, abuts the step 47 of the control block 3. In order to avoid having to place the opposite bore 55, which is assigned to the pressure supply connection point P and which the receiving plate 39 must bypass, at too great a distance to the displacement axis, the recess 41 for the passage of the valve casing 1 in the receiving plate 39 is not arranged centrally, but rather eccentrically. Thanks to this eccentric arrangement, the step 47 on the side of the bore 55 is located at a lesser distance to the displacement axis than the step 47 in the region of the opposite bore 57. Accordingly, the bore 55 can, although it must bypass the receiving plate 39, be arranged at approximately the same distance from the displacement axis of the valve piston 5, as in the case of the bore 57 which helps to achieve a compact design.

Because the control chamber 49 adjoining the top side of the receiving plate 39 conducts the pressure of the supply connection point P, while the control chamber 51 adjoining the bottom side conducts the pressure of the service connection point A, the connection plate 39 applies a load to the step 47 in the installation space due to the fact that, during operation, the pressure in the top control chamber 49 is greater/equal to the pressure in the lower control chamber 51. Thus, in spite of the eccentricity, there is no bending moment acting on the valve body 1, which could lead to jamming of the valve piston 5.

Thanks to the ability to form the bores 55, 57, 59 forming the connection channels axially parallel to the displacement axis of the valve, which eliminates the need to form transverse bores in a respective casing, which forms the installation space for the respective cartridge valve, the valves can be flanged directly on a transmission casing, or the transmission casing itself can form, by means of parts, installation spaces, which perform the function of respective control blocks. In other words, the invention also permits a direct installation of the control device in transmission casings, because no transversal casing bores are required. 

1. A control device for selectively fluidically connecting and disconnecting fluid connection points (A, P, T) by means of a valve apparatus (1, 5), which controls fluid-conducting connection channels (55, 57, 59) extending between the connection points (A, P, T), which connection channels are arranged in a control block (3), into which the valve apparatus (1, 5) is at least partially inserted, characterized in that, proceeding from the respective fluid connection points (A, P, T), the connection channels (55, 59, 57) respectively connected to the fluid connection points are arranged extending parallel to each other until the connection channels open into a respective assigned control chamber (49; 53, 51) of the valve apparatus (1, 5) and that the valve apparatus (1, 5) is held in a receptacle (39), which separates at least two adjacently arranged control chambers (49, 51) from each other.
 2. The control device according to claim 1, characterized in that the valve apparatus (1, 5) is provided with a casing (1), which itself at least partially forms a control chamber (53) and/or which has at least one bore (50, 52) opening into a control chamber (49, 51).
 3. The control device according to claim 1, characterized in that, in view of the parallel arrangement of the connection channels (55, 59, 57), the receptacle (39) for the valve apparatus (1, 5) is accommodated eccentric relative to the displacement axis of the valve gate (5), which is longitudinally-displaceably guided inside the valve casing (1), in the control block (3).
 4. The control device according to claim 1, characterized in that the receptacle is formed from a circular cylindrical receiving plate (39), which has a preferably circular cylindrical recess (41) for receiving the valve casing (1), the center axis of which, extending parallel to the center axis of the receiving plate (39), is arranged offset relative to same.
 5. The control device according to claim 1, characterized in that the connection channel (55) for the pressure supply connection (P) and the connection channel (57) for the service connection (A) take up, with their respective longitudinal axis, at least approximately the same distance to the displacement axis of the valve gate (5) and that the longitudinal axis of the connection channel (59) for the tank connection or return connection (T) is coextensive with the displacement axis of the valve gate (5).
 6. The control device according to claim 1, characterized in that the pressure supply connection channel (55) extending in the control block (3) is formed such that it is longer than the service connection connecting channel (A) in the axial direction, and this, in turn, is formed such that it is longer than the tank connection channel (59). (Currently amended) The control device according to claim 1, characterized in that the control chamber (49) into which the pressure supply connection channel (55) opens lies above the control chamber (51) into which the service connection connecting channel (57) opens, viewed in the actuation direction of the valve gate (5), and that these two control chambers (49, 51) are separated from each other in a fluid-tight manner by means of the receptacle (39).
 8. The control device according to claim 1, characterized in that the control chamber (51) into which the service connection connecting channel (57) opens lies above the control chamber (53) into which the tank connection channel (59) opens, viewed in the actuation direction of the valve gate (5), and that these two adjacent control chambers are separated from each other in a fluid-tight manner by means of valve casing parts (43), which are encompassed by parts (42) of the control block (3).
 9. The control device according to claim 1, characterized in that the plate (39) of the receptacle is encompassed on the outer peripheral side by a sealing device (45), which produces the seal between the receptacle (39) and the control block (3).
 10. The control device according to claim 1, characterized in that the control block (3) is a component of a transmission casing, in particular a mobile work machine, or can be attached to the transmission casing. 